The European Air and Space Agency issued orders on the PW1100G engine powered NEO’s in a certain range of serial numbers that expects to ground around 21 aircraft. They are not permitted to complete more than three cycles before grounding.
The danger is that both engines could shut down simultaneously or within a short time of one another.
The cause is a rubber seal in the high pressure containment chamber and affects 43 engines.
ETOPS flights have been suspended and P&W say they have a solution, but the geared turbofan engine is continuing to cause pre and post delivery issues.
Qatar recently agreed to take delivery of its A320neos held in storage as long as they were re-engined with the LEAP plant and the P&W’s removed.
Most airlines are resigned to having to deal with the issues in the eventual knowledge that they’ll all be fixed and problems ironed out, but I understand that the number of orders for the P&W engine have been in decline.
Bombardier also use the engine on the CSeries and blame P&W for late delivery of aircraft.